As in any specialized profession, the world of ESL/EFL/ELL has its own unique terminology. I quite regularly come upon words that I’m not familiar with.
I thought a short “The Best…” list might be useful for readers.
I haven’t found one glossary of these kinds of terms that I would consider “complete” and accessible, so I’m listing a few of them.
Here are my picks for The Best Guides To ESL/EFL/ELL Terminology:
A (Mostly) Complete Glossary for ESL EFL Teaching From Heads Up English (I would say that this is the best one on this list)
The last two were suggested by David Deubelbeiss. Thanks, David!
The American Institutes For Research has a good document titled Common ELL Terms and Definitions.
Colorin Colorado has a good glossary.
Other suggestions are, as always, welcome.